Rotary tool for cutting stationary bars of material



Oct- 5, 1957 G. E. MENZIES 2,809,697

ROTARY TOOL FOR CUTTING STATIONARY BARS OF MATERIAL Filed Feb. 24, 1955 United States Patent ROTARY TOOL FOR CUTTlNG STATIQNARY BARS OF MATERIAL George Elgin Menzies, Wentworth Falls,

' New South Wales, Australia Application February 24, 1955, Serial No. 490,341 Claims priority, application Australia March 22, 1954 3 Claims. (Cl. 164-60) This invention has reference to rotary tools for cutting stationary bars'of material, more particularly metal, either into lengths or so as to form, for example, a straight or tapered screw threaded portion; or so as to produce a re duced portion on a section of the bar.

More particularly the invention has been devised to provide for automatic cutting of stationary bars arranged to be fed vertically to the tool, but the tool can be used'ior cutting bars fed horizontally or at any convenient angle. The tool could if so desired be designed as part of a portable power-driven contrivance adapted to cut bars while they remain on a rack as in the store-room of an engineering establishment. It has many other uses including the flaring of the ends of copper pipes.

The invention is characterised in that the tool is designed to operate efficiently at high speeds, and it can be provided at comparatively small expense. It has few moving parts and does not require springs. More especially it is intended for cutting bars of the softer metals such as brass.

Primarily, the improved tool is intended to be poweroperated, but with the aid of manually operated means of known type it could, for instance, be utilised to cut relatively thin tubular bars.

Another feature of the invention is that the cutters of the tool are so arranged that metal shavings are thrown freely from the tool without obstructing the tool or upsetting its balance.

A further feature of the invention resides in the fact that the cutters thereof can be moved manually or automatically to make a lighter or heavier cut while the tool is revolving at high speed.

Primarily the invention consists in mounting one or more pivoted cutters on one face of a casing which houses a block with a cam face or faces whereby said cutter or cutters can be adjusted for the work in hand. The said casing is aflixed to or formed integral with a hollow stock through which the bar to be out can be fed, or which can be pushed onto one end of the bar as when the tool forms part of a portable power or handdriven unit.

In order however that the invention may be clearly understood and readily carried into practical eiiect reference is nOW made to the accompanying drawings, where- Figure l is an elevation of the improved tool in simple form.

Figure 2 is a plan of the tool illustrated by Figure 1.

Figure 3 is a sectional-plan of the tool taken on the horizontal-plane 3-3 indicated in Figure 1.

Figure 4 is a section of the tool taken on the vertical planes 4-4 indicated in Figure 3.

Figure 5 is a somewhat diagrammatic elevation showing the tool being operated horizontally by an electric motor.

Fig. 6 is a section of the tool taken on the oblique plane 6-6 indicated in Fig. 3.

2,809,697 Patented Oct. 15, 1957 The simple construction illustrated by Figures 1 to 4 inclusive is characterised mainly in that three arcuate cutters 10 are secured in pivoted holders or arms 11 on the upper face of a casing 12. Within the casing 12 there is an adjusting member 13 with three angularly disposed circular cam tracks 14 one of which appears in Figure 4. In this particular instance the member 13 takes a form approaching that of a propeller as seen in Figure 3: that is because extraneous material has been cut away from a block to make the member 13 lighter in weight. A hollow adjusting-sleeve 15 is formed integral with the member 13.

The casing 12 is aflixed to the upper end of a hollow stock 16 through which the bar of material to be cut, is fed, and said casing is intended to be rotated about its axis at high speed, through the medium of suitable means of known type affixed to said stock 16.

The tool is shown vertically in Figure 1 because one or a plurality of them can be conveniently arranged in that position, in an appropriate bed or table and provision made for rotating them as by an electric motor and worm gearing. Such an arrangement allows of the work (a solid or tubular bar) being fed by gravity through the hollow stock 16.

Reverting now to the three arcuate cutters 10 it will be observed on reference to Figures 1 and 2 that each of these is secured in its pivoted arm or holder 11 by means of a tapered arcuate key 17 which is driven tightly into position in the manner of a wedge.

Each pivoted arm or holder 11 is fast on the protruding end portion of a stub-shaft 18. On reference to Figure 4 it will be seen that those shafts 18 have an upper shoulder 19 and a lower shoulder 20 which bear against the roof 21 and floor 22' respectively, of the casing 12. Looking at Figure 3 in conjunction with Figure 4 it will be seen that each shaft 18 also has integral with it a lateral arm 23. Pins 31, upon which balls 24 are freely mounted, at the extremity of lateral arms 23, extend through narrow longitudinal slots 32 in the cam tracks 14 (shown in Fig. 6 Each ball 24 fits comfortably in one of the cam tracks 14 in the member 13. The tracks 14 are disposed at such an angle to the axis of the tool that when the. member 13 is moved axially in one direction the several cutters 113 will be moved in unison so that their cutting tips will approach the axis of the tool; and when the member 13 is moved axially in the opposite direction the cutting tips will simultaneously recede from said axis.

Axial movement of the member 13 is preferably effected through the medium of a collar (not shown in Figures 1 to 4 inclusive). Such an arrangement is however indicated in Figure 5 where the tool is supported for rapid rotation about a horizontal axis. In that exemplification of the invention which lends itself to an explanation of the manner in which the improved tool is put into use, the electric motor 25 has a hollow driving shaft (not shown) which allows of the work-a rod 26being fed through the motor to the tool. The driving shaft of the motor 25 is coupled to the hollow stock 16 by flanges 27; and a thrust-race 28 on the hollow adjusting sleeve 15, allows of the member 13 being advanced and withdrawn to move the tips of the cutters 18 toward the axis of the tool and away from it as circumstances demand. In that connection it is explained that when the member a 13 is moved toward the roof 21 of the casing 12 the cam tracks 14 bear against the balls 24 and cause the arms 23 to partly rotate the stub-axles 18. That rotary movement of the stub-axles 18 causes the pivoted arms or holders 11, with the cutters 10 secured therein, to move toward the axis of the tool.

The handle 29 in Figure 5 provides for manual control of the member 13, whereas the horizontal shaft 30 is intended to impart axial movement automatically to the member 13 from a pattern (not shown) as in the performance of transfer work.

Whether the tool is arranged to be spun vertically or horizontally, it will be recognised that a concerted move: ment of the cutters 11), so that their tips approach the axis of the tool as the latter is rotated at high speed, will cause a tube or bar fed through the stock 16 thereof to be quickly severed.

For centering purposes in setting up the tool a close fitting plug (not shown) with an appropriate tip may be inserted in the hollow stock 16.

If desired several of the tools could be mounted for operation in the form of a horizontal or vertical turret. Also, the manner in which the cutters are mounted could be reversed so that the tool instead of being used for cutting into the outer surface of a bar, could be employed for boring, reaming, recessing, or inside screwing, and like purposes. 7

In use the casing of the tool should be filled with oil or a light-weight greaseof suitable consistency to provide ample lubrication for the member 13 and the balls 24 in the cam tracks 14.

It will be understood that instead of having cutters 19 the pivoted holders or arms 11 may carry die chasing attachments, thread cutters and the like adapted to operate from zero diameter to full diameter of the bar. Also, for instance, suitable cutters may be provided to cut reverse tapers in or on the work.

I claim:

1. A rotary tool for cutting stationary bars of material comprising an elongated hollow stock through which a bar of material may be fed lengthwise so as to project from an end of said stock, a casing connected to and surrounding said stock, said casing and said stock defining a chamber adapted to receive oil or the like for lubricating parts located within said chamber, a turnable shaft extending through a wall of said casing in a direction substantially parallel to said hollow stock, a cutter carried by said shaft exteriorly of said casing and adjacent the end of the hollow stock from which a bar of material may extend, a sleeve mounted on said hollow stock for axial movement with respect thereto in opposite directions, a member extending from said sleeve and located within said chamber, said member including a cam track having an axis inclined with respect to the axis of the elongated hollow stock, an arm extending from the cutter supporting shaft, and means carried by said arm and located within said cam track for engagement by said cam track, said cam track engaging said arm carried means to turn said cutter supporting shaft in one direction during axial movement of said sleeve in one direction, and engaging said arm carried means to turn said cutter supporting shaft in the opposite direction during opposite axial movement of said sleeve.

2. A rotary tool for cutting stationary bars of material comprising an elongated hollow stock through which a bar of material may be fed lengthwise so as to project from an end of said hollow stock, a hollow casing connected to and surrounding said hollow stock, said casing having a top wall, side wall, and bottom wall, said walls and said hollow stock defining a chamber adapted to contain oil or the like for lubricating movable parts located within said chamber, a plurality of turnable shafts projecting through the top wall of the casing, each shaft carrying a cutter, a sleeve having a portion extending between the bottom wall of the casing and the hollow stock, said sleeve surrounding and being slidable on said hollow stock, and a plurality of arms extending from said sleeve and located within said chamber, there being an arm for each cutter'carrying shaft, each arm including means engaging means extending from each cutter carrying shaft to positively turn the shaft in one direction during sliding movement of the sleeve in one direction and to positively turn the shaft in the opposite direction during opposite sliding movement of the sleeve, movement of said sleeve causing said shafts to turn together to move the cutters simultaneously toward or away from the longitudinal axis of said hollow stock depending upon the direction of movement of the sleeve.

3. A rotary tool according to claim 2 wherein each arm extending from the slidable sleeve includes a cam track adjacent the end of the arm, said cam track being inclined with respect to the longitudinal axis of the hollow stock, and the means extending from each cutter carrying shaft and engaged by a cam track is a ball member located within said cam track, said cam track being movable with respect to said ball member. 9

References Cited in the He of this'patent UNITED STATES PATENTS 

